In Tucson, Saving the Bath Water Too

By Amy Feldman

Would you water your garden with what goes down your shower drain or out your washing machine? In Tucson, Arizona, and an increasing number of water-starved western cities, more and more residents are saying yes.

If you've never contemplated what happens to the water that gets you or your clothes clean, you're far from alone. But for cities and environmentalists trying to head off the growing threat of drought and rising water costs, so-called graywater  differentiating it from the "black water" that goes down the toilet  is getting a lot more attention. A decade ago, Tucson, which has about a million residents in its metro area and is a liberal and environmentally conscious oasis in a red state, convinced Arizona legislators to make it legal for homeowners to irrigate their trees and plants with the water that was going down their drains or out of their washing machines without a permit. Now, graywater use is not only legal in Tucson, and indeed the rest of Arizona, but promoted, and, in some cases, required. In 2007, the state rolled out a tax credit of up to $1,000 for homeowners who install graywater systems. Last year, a law  believed to be the country's first  went into effect in Tucson that requires builders to include graywater plumbing in new construction. (See pictures of how cities are powered.)

"If there are higher stages of drought, there will be more watering restrictions," says Ilene Grossman, who is the city water department's conservation program manager. "We're not at the critical stage right now, but we are planning for that."

There's not good data on how close our nation's cities are to a water crisis, or how many people are using graywater. But the picture is this: Climate change, the cost of water treatment and rising populations will eventually, if nothing is done, run some US cities, particularly western ones, dry. Tucson, for instance, is already in what's called stage one drought, which means it's too dry but not yet critical. If a worse drought were to occur, there would be restrictions on gardening. Outside of desert areas like Tucson, there's issues of climate change and the cost of building sewage treatment plants to accommodate an expanding population. "It's crazy that we do so much to get water, and then it gets dumped down the drain," says Laura Allen, a founding member of Greywater Action, who set up her own Oakland, California home's graywater system illegally and has advocated for California's recent rule changes. (See more about intelligent cities around the world.)

A number of city and state legislatures are coming to the same conclusion. Depending on the climate and the size of the yard, graywater reuse can lower a household's total consumption by as much as 40%. In November, Pacific Institute, which is an influencing water conservation research group, said that graywater reuse was an important strategy in improving a city's water resiliency against climate change. At a time of tight budgets, increased graywater usage could reduce the need for cities to spend money on costly new water supply projects. "It's almost at the tipping point where there are more states in the west that have graywater regulations than those that do," says Val Little, director of the Water Conservation Alliance for Southern Arizona (Water CASA).

In Tucson, where the desert climate means that people typically spend at some 45% of their daily water usage irrigating their yards, graywater was something of a no-brainer. Brad Lancaster, an independent water consultant in Tucson, personally started harvesting graywater in 1993, and recalls how he and other graywater wildcatters would share ideas about what worked and what didn't. In Tucson, unlike in colder climates, many people keep their washing machines outside, in sheds or garages, and creating an ad-hoc hookup to water the always-thirsty trees was too easy to pass up.

When Water Conservation Alliance for Southern Arizona surveyed graywater usage from 1998 to 2000, it discovered that 13% of single-family homes in the area were already using graywater systems  illegally. "It was a wake-up call," says Little, who used the data to push through the legislation. The same study found no significant health risks from these wildcat graywater setups, though it recommended that kitchen sinks be excluded because of the potential for contamination. (See TIME's video "What Makes a City Smart?")

To get Tucsons to go grey, the city first got rid of the cumbersome permitting process, which many were ignoring anyway. Second, the city's water department, Water CASA and others began hosting workshops. Demonstration sites have been set up, including one at a Habitat for Humanity house, so that locals can see what's doable. Last, city officials have stressed that reconfiguring plumbing is not as expense as you would think. Tucson Water's Grossman estimates that a simple system can be built out for a few hundred bucks, while a more expensive one that requires pumping for pipes that are below-grade could run a few thousand. "You can build something really cheaply," says Grossman.

The potential for health risks, too, are minimal, as long as you take simple precautions. If you use your washing machine for graywater, for example, you need to be able to switch it to the sewer system if you're laundering dirty diapers or using bleach. You'll obviously want to be careful about detergent choices, picking something not only biodegradable (no phosphates, no boron) but low in salt. And you have to watch that graywater doesn't pool outside, which could attract mosquitoes and disease. Read "Want to Improve Your City? There's an App for That."

Unfortunately, the ordinance that might put Tucson furthest ahead in water conservation is effectively on hold because of the housing bust. With few new homes being built, developers have yet to construct many graywater-ready houses. Still, other cities are already looking to Tucson as a model. Rodney Glassman, the former city councilman who pushed for the law (before leaving the council to run, unsuccessfully, for Senate against John McCain), has been talking to city councils in Flagstaff, Mesa and other Arizona communities about the new graywater and rainwater rules. "The majority of councils are Republican, but in Arizona conservation isn't a partisan issue," Glassman says.

In fact, both Glassman and Little say they've been taking the show on the road, talking to government officials and conservation proponents from San Francisco to Atlanta. "I think we're on the forefront of graywater harvesting," consultant Lancaster says. "But graywater is just a piece of the equation. Stormwater harvesting, rainwater harvesting and air-conditioning condensate harvesting are all other pieces. The key thing is that we need to make all these strategies legal  it's better than recycling."